Shears for trimming sheet metal



I... FRIELINGHAUS SHEARS FOR TRIMMING SHEET METAL Filed Feb. 23, 1935 BYi:

ATTORNEY.

Patented Feb. 25, 1936 UNETED STATES PATENT OFFICE SHEARS FOR TRIMMIINGSHEET METAL Application February 23, 1935, Serial No. 7,859 In GermanyDecember 27, 1933 3 Claims.

My invention relates to a shear for trimming sheet metal andparticularly to the means for guiding and supporting the sheets orpackets of sheets while being trimmed along their edges by the circularblades of the shear. For this purpose, rollers are generally providedwhich engage the sheets from the top, and which are so arranged as tolie in one horizontal plane, a similar series of rollers being alsoprovided for engaging the sheets from the bottom. The sheets aretherefore constrained to adjust themselves into horizontal planes attheir points of contact with the rollers. Since the sheets are usuallyfed to the trimming shear directly after their passage through therolling mill, without first being operated upon by a straighteningmachine, the sheets are liable to exhibit a very marked curvature in onedirection so that, when being passed between the rollers of the shear,they are submitted to heavy stresses and bulge out considerably towardsthe opposite side at those places where they are not gripped by therollers. This, of course, is very undesirable since the sheets will bedeformed unevenly throughout their length and the trimmed edges willtherefore not be exactly parallel.

The object of my invention is to provide a shear for trimming sheetmetal in which the aforementioned drawbacks are avoided. This Iaccomplish by arranging the guiding and supporting rollers of the shearin planes which match as closely as possible the curvature of the sheetsthat are to be trimmed so that the sheets will no longer be deformedwhen introduced between the rollers. Means are also provided to adjustthe rollers to different curvatures and thicknesses of the sheets orpackets of sheets.

The invention is illustrated by way of example in the accompanyingdrawing in which Fig. 1 is a side elevation of a trimming shear,according to the invention,

Fig. 2 is an end elevation, and

Fig. 3 a plan view of the guiding and supporting rollers and the partsassociated with them.

The shear according to this invention comprises two pairs of circularblades a for trimming sheets or packets of sheets which, since they donot form part of the invention, are represented in a purely diagrammaticmanner and without their driving means.

For guiding and supporting the sheets or packets of sheets which areintroduced into the shear, rollers b are provided which are arranged ina plurality of parallel rows above and below the sheets so as to engagethe latter both from the top and the bottom. The rollers b are mountedin suitable carriers 0.

According to this invention the rollers b are so located as to match thecurvature of the sheets delivered to them. As a rule, this curvature isdetermined by conditions which are not liable to change during theoperation of the shear. Means not shown here can however be provided tovary the position of each individual roller 1) so as to vary also thecurvature defined by the whole set of rollers. The sheets will usuallyexhibit a marked curvature only in one direction, 1. e. either parallelor normal to the trimmed edges, so that the rolls will be adjustedeither in the position of Fig. l or Fig. 2.

The roller carriers 0 are connected with one another by lazy-tongsmechanisms 01, for the purpose of keeping the distance between theroller carriers constant for different positions of the shears a.

The upper and lower roller carriers 0 embrace by means of stirrups e thetransverse beams j that support them, against which they bear by meansof screws 9. By adjusting these screws the distance between the upperand lower carriers can be Varied, and therefore also the distanoebetween the rollers 17 mounted thereon. The packets of sheets are fed tothe circular shears in the direction of the arrow in Figure 1 over afeed table it, and are then engaged by the rollers b, while they are cutby the shears a at these edges, and then carried away on the dischargetable 2'. The tables h and z are likewise so constructed that they adaptthemselves to the curvature of the packets of sheets.

My invention can also be applied to shears which have more than twopairs of blades, such as shears for slitting metal sheets.

I claim as my invention:

1. A shear for trimming metal sheets, comprising, in combination with aplurality of cutters, a plurality of groups of guiding and supportingrollers adapted to engage the sheets from above and below in thedirection of feed and disposed along a curve conforming to thelongitudinal and transverse curvature of the metal sheets to be trimmed,and means for adjusting the position of each individual group of saidrollers relative to the sheets.

2. A shear for trimming metal sheets, comprising in combination with aplurality of cutters, a plurality of groups of guiding and supportingrollers adapted to engage the sheets from above and below in thedirection of feed and disposed along a. ourve conforming to thelongitudinal and transverse curvature of the sheets to be trimmed, andconveying rollers provided in advan-2e of and after said guiding and.supporting rollers and likewise disposed along a curve eonforming to thelongitudinal curvature of the metal sheets to be trimmed.

3. A shear for trimming metal sheets, compris- 0 ing, in combinationwith a plurality of cutters,

a. plurality of groups of guiding and supporting rollers adapted toengage the sheets from above and below in the direction of feed anddisposed along a curve conforming to the longitudinal and transversecurvature of the metal sheets to be trimmed, carriers for each group ofsaid rollers, and means for adjusting the position of each carrierindependent of the other carriers.

